Database Reference
In-Depth Information
Even though vSphere has been “NUMA aware” for a very long time, in vSphere 5
VMware introduced vNUMA. vNUMA helps optimize the performance of a virtual
machine too large to fit within a single NUMA node and must span NUMA boundaries
by exposing to the guest operating system the actual physical topology so that it can
make its own NUMA decisions. This is good news for large-scale SQL Server
workloads that are virtualized that cannot fit within a single NUMA node.
A great blog article titled “vNUMA: What It Is and Why It Matters” can be found at
As we discussed earlier, NUMA and the ability to hot-plug a CPU should not be used in
combination with each other.
Tip
vNUMA is disabled if vCPU hot plug is enabled. The link to the VMware
knowledge base article is
http://kb.vmware.com/kb/2040375
.
To learn more about NUMA nodes, see the VMware technical white paper, “The CPU
Scheduler in VMware vSphere 5.1,” which can be found at
Sizing the Individual VMs
Memory is a very valuable resource that, as you have learned in this chapter, can greatly
affect the performance of your database in a number of ways. When you build out the
virtual machines, it's important to keep them as lean as possible. This will help you
with your NUMA boundaries. This will also help make sure you are efficiently using the
resources you have available to you. In this shared environment, it will help ensure
adequate memory is available for the hypervisor to share among the many individual
virtual machines running on the physical host.
Your virtualized database is sitting on a shared environment. To ensure quality of
service means making sure the database has the resources it needs in the context of a
shared environment. This is why we put so much emphasis on resource guarantees for
resources such as memory. By building your VM as efficiently as possible, you help
make sure there are enough of the shared resources for everyone.
Caution
When you create your virtual machines, keep the footprint as lean as possible.
Don't install database and Windows operating system features you will not need.
Make sure you disable all unnecessary foreground and background processes.
